Data from the US Military Railway Service's Equipment Data Book for Italian Locomotives supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also "2-8-2 Express and 4-8-0 Compound Goods Locomotives: Italian State Railways", Locomotive Magazine, Volume XXVII [27] (15 July 1921), p. 171; "Four-Cylinder Compund Locomotive, Italian State Railways", Locomotive Magazine, No 368 (14 April 1923), pp. 98-99; and Wikipedia's "FS Class 746" entry at [], last accessed 23 February 2021.
Ugo Poddine, in his contribution to Bryan Attewell ([] Steam simulation (April 2000), says four of the 746 class of Mikados (Locobase 2506) were converted to a four-cylinder simple-expansion layout as shown here. See also Nino Carbone, "Gr 746 FS" entry posted 25 April 2015 in the Italia - Locomotive a vapore forum on the Marklinfan Club Italia website at [
], last accessed 15 July 2021.
Data from Ugo Poddine as contributor to Bryan Attewell ([] Steam locomotive simulator (April 2000). Additional data from the US Military Railway Service's Equipment Data Book for Italian Locomotives supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.
Principal Dimensions by Steve Llanso of Sweat House Media | |||
---|---|---|---|
Class | Gruppo 746 | Gruppo 746.046 | Gruppo 940 |
Locobase ID | 2506 | 3683 | 3690 |
Railroad | Ferrovie dello Stato (FS) | Ferrovie dello Stato (FS) | Ferrovie dello Stato (FS) |
Country | Italy | Italy | Italy |
Whyte | 2-8-2 | 2-8-2 | 2-8-2T |
Number in Class | 42 | 4 | 53 |
Road Numbers | 746.046, 746.106, 746.007, 746.107 | ||
Gauge | Std | Std | Std |
Number Built | 42 | 53 | |
Builder | Breda | Breda | several |
Year | 1921 | 1931 | 1922 |
Valve Gear | Walschaert | Walschaert | Walschaert |
Locomotive Length and Weight | |||
Driver Wheelbase (ft / m) | 19.49 / 5.94 | 15.42 / 4.70 | |
Engine Wheelbase (ft / m) | 36.88 / 11.24 | 32.51 / 9.91 | |
Ratio of driving wheelbase to overall engine wheelbase | 0.53 | 0.47 | |
Overall Wheelbase (engine & tender) (ft / m) | 66.17 / 20.17 | 32.51 / 9.91 | |
Axle Loading (Maximum Weight per Axle) (lbs / kg) | 35,640 / 16,166 | 35,715 / 16,200 | |
Weight on Drivers (lbs / kg) | 142,562 / 64,665 | 142,859 / 64,800 | 135,520 / 61,471 |
Engine Weight (lbs / kg) | 206,359 / 93,603 | 206,793 / 93,800 | 192,060 / 87,117 |
Tender Loaded Weight (lbs / kg) | 110,220 / 49,995 | ||
Total Engine and Tender Weight (lbs / kg) | 316,579 / 143,598 | 192,060 / 87,117 | |
Tender Water Capacity (gals / ML) | 5808 / 22 | 6378 / 24.16 | 2750 / 10.42 |
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 6.60 / 6 | 5.50 / 5 | 3.30 / 3 |
Minimum weight of rail (calculated) (lb/yd / kg/m) | 59 / 29.50 | 60 / 30 | 56 / 28 |
Geometry Relating to Tractive Effort | |||
Driver Diameter (in / mm) | 74 / 1880 | 74 / 1880 | 53.90 / 1369 |
Boiler Pressure (psi / kPa) | 206 / 14.20 | 227.70 / 15.70 | 174 / 12 |
High Pressure Cylinders (dia x stroke) (in / mm) | 18.11" x 26.77" / 460x680 | 17.72" x 26.81" / 450x681 (4) | 21.3" x 27.6" / 541x701 |
Low Pressure Cylinders (dia x stroke) (in / mm) | 28.35" x 26.77" / 720x680 | ||
Tractive Effort (lbs / kg) | 29,508 / 13384.62 | 44,036 / 19974.42 | 34,360 / 15585.45 |
Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.83 | 3.24 | 3.94 |
Heating Ability | |||
Tubes (number - dia) (in / mm) | 185 - 2.047" / 52 | 135 - 2.03" / 52 | |
Flues (number - dia) (in / mm) | 27 - 5.236" / 133 | 27 - 5.236" / 133 | 21 - 5.25" / 133 |
Flue/Tube length (ft / m) | 19.03 / 5.80 | 19 / 5.79 | 16.39 / 5 |
Firebox Area (sq ft / m2) | 182.99 / 17 | 129.12 / 12 | |
Grate Area (sq ft / m2) | 46.29 / 4.30 | 46.29 / 4.30 | 30.13 / 2.80 |
Evaporative Heating Surface (sq ft / m2) | 2774 / 257.70 | 2584 / 240.06 | 1646 / 152.97 |
Superheating Surface (sq ft / m2) | 721 / 67 | 1206 / 112.08 | 444 / 41.26 |
Combined Heating Surface (sq ft / m2) | 3495 / 324.70 | 3790 / 352.14 | 2090 / 194.23 |
Evaporative Heating Surface/Cylinder Volume | 347.57 | 168.83 | 144.61 |
Computations Relating to Power Output (More Information) | |||
Robert LeMassena's Power Computation | 9536 | 10,540 | 5243 |
Same as above plus superheater percentage | 11,538 | 13,913 | 6344 |
Same as above but substitute firebox area for grate area | 45,612 | 27,185 | |
Power L1 | 13,221 | 8634 | |
Power MT | 817.81 | 561.83 |